Cylindrical roller stent crimper apparatus with radiation shield

Abstract

A stent loading apparatus for loading a deformable stent onto a deployment device. The stent loading apparatus includes an elastic member defining a passage therein formed for longitudinal receipt of the deformable stent in an uncrimped condition. A first member includes a first compression region; and a second member includes a second compression region positioned substantially adjacent the first compression region at a first position. At this first position, the elastic member and the deformable stent in the uncrimped condition may be received between the opposed first and second compression regions. The first compression region and the second compression region are further configured to provide rolling support and compression of the elastic member during relative movement between the first position and a second position for rolling radial compression of the deformable stent onto the deployment device.

Description

The present invention relates, generally, to intravascular stents and, more particularly, to stent crimping apparatus with radiation shields for radioactive stents.Percutaneous Transluminal Angioplasty (PTA) is a medical procedure for widening a stenosis or constriction of a bodily passage. The most common application is to widen the passage of a blood vessel, such as an artery, which has been constricted by the build-up of cholesterol fats or atherosclerotic plaque. When this medical procedure is applied to a coronary artery, it is referred to as Percutaneous Transluminal Coronary Angioplasty (PTCA).Typically, a tip mounted balloon of a balloon catheter is advanced over a guidewire to the stenosis. Once the balloon catheter is properly position, the balloon is inflated to compress the plaque against the vessel walls and widen the stenosis. Problems occur, however, when the dilatation of the occlusion forms fissures, flaps and / or dissections which may ultimately cause reclosure or r...

AI Technical Summary

Benefits of technology

In one configuration, a gear assembly is included which is formed to cooperate with the crimper body, the spindle member and the deployment device to provided for rolling support of the stent between the first position and the second position. The gear assembly preferably includes a drive gear coupled to the crimp roller, an internal gear coupled to the crimper body, and a spur gear driveably meshed between the drive gear and the internal gear. The spur gear is further coupled to the deployment device to facilitate movement of the stent between the first position and the second position.

One other aspect of the present invention provides a shielded stent crimping assembly for loading a radioactive stent onto a deployment device. This assembly includes a crimping mechanism adapted to crimp the radioactive stent onto the deployment device. A shielded crimper body defines a bore portion formed for receipt of the radioactive stent and the crimping mechanism therein. The crimper body and the crimping mechanism cooperate to substantially prevent the passage of radiation from the bore portion during crimping of the stent by the crimping mechanism.

Problems solved by technology

Problems occur, however, when the dilatation of the occlusion forms fissures, flaps and / or dissections which may ultimately cause reclosure or restenosis of the vessel.

The performance of these tools, however, is not completely satisfactory since there is still a wide divergence between application force, profile and stent diameter.

Problems arise when excessive crimping forces are applied to the crimp pliers which can damage the stent and / or balloon catheter.

This is especially problemsome given the minute size of the stents which are typically on the order of about one (1) mm to four (4) mm in diameter before crimping.

Moreover, non-uniformity of the crimping may be experienced as well as the inability to determine when a reliable and uniform crimp has been achieved.

Thus, maintaining such an inventory is not only difficult to store, but can be very expensive as well.

The proper crimping of a stent about a balloon catheter, however, is a technique acquired only through practice and can be affected by a variety of subjective conditions.

Too much or too little pressure may be applied and the balloon and / or stent may be damaged, lost, or may not otherwise perform as desired during the procedure.

In contrast, the physician may not apply sufficient crimping pressure to the stent to load it onto the balloon.

During advancement through the vessel or upon deployment, an insufficiently crimped stent may slip or rotate on the catheter during, or in the worst case scenario, come off the balloon catheter entirely; the result of which is not desirable.

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